I want to upgrade my power supply so that i can upgrade my graphics card. my question is, does it mater which way the fan is facing in my case. i have a dell studio 540 and my psu mount is at the top of the case. most of the power supplies ive been looking at have a fan on top of them. i was wondering if it matters if the fan is going to be facing the top of my case? or should i find a psu that has a fan blowing out the back like the stock one i have now. the two psu's im looking at are http://www.newegg.com/Product/Product.aspx?Item=N82E16817371035 and http://www.corsair.com/gs600w.html?___store=es&___from_store=en. thank you for your time and plz feel free to ask any questions if im not being clear on my question